Laser barrier

ABSTRACT

A laser shield consists essentially of a series of spherical glass bubbles densely packed within a range of 1.95×10 3  bubbles per cubic centimeter to 1.25×10 8  bubbles per cubic centimeter encapsulated in a matrix of silicone to provide a flexible and lightweight foam-like material to terminate CO 2  laser radiation without producing a substantial carbon plume. The glass bubbles may be filled with a gas. In another embodiment, a laser shield consists essentially of water encapsulated in a matrix of silicone to provide a flexible and lightweight material to terminate CO 2  laser radiation without producing a substantial carbon plume. In another embodiment, water bubbles and glass bubbles are both encapsulated within a matrix of silicone to provide a laser shield. A surgical drape, a surgical sponge and an endotracheal tube are formed of a flexible and lightweight material of a series of densely packed bubbles encapsulated in a matrix of silicone to terminate laser radiation.

TECHNICAL FIELD

This invention relates to a laser shield.

BACKGROUND

High powered infrared lasers have been widely used for a number ofdifferent applications. For example, lasers are now being widely usedfor medical therapy and surgical techniques wherein tissues are repairedand/or removed through the use of high energy lasers, such as producedby CO₂ (10.6 um wave length) lasers operating at irradiance levels ofabout one kw/cm² and higher.

A need exists to provide protection in areas where high energy lasersare being used to prevent burning of tissue or objects. Solid metallicshields used to absorb or reflect laser radiation are frequently notadaptable to many situations.

It is therefore desirable not only to protect personnel and othersurrounding objects from incoming laser radiation, but it is alsodesirable to be able to terminate such laser radiation with a substancewhich may be readily formed into many shapes and is flexible so as to bemanipulated for a wide variety of applications and uses.

BRIEF SUMMARY OF THE INVENTION

A laser shield is formed of densely packed bubbles which areencapsulated within a matrix of silicone for providing protection fromlaser radiation.

In one form, the bubbles consist of glass bubbles which reflect andrefract laser energy to such a degree that the silicone diffuses thelaser energy without producing a substantial carbon plume. Such glassbubbles may, if desired, be filled with a gas, such as argon or heliumfor example, which further produces an absorbing effect upon theincoming laser radiation.

In another form, the laser shield consists essentially of waterencapsulated in a matrix of silicone to provide a flexible material toterminate CO₂ laser radiation without producing a substantial carbonplume. The water can be formed in layers surrounded by the silicone orit can be stirred into the silicone to produce numerous bubbles whichare densely packed and encapsulated by the silicone matrix.

In still another form, water bubbles and glass bubbles are both combinedand encapsulated by the silicone to provide a laser terminating shield.

The bubbles are densely packed within a range of 1.95×10³ bubbles percubic centimeter to 1.25×10⁸ bubbles per cubic centimeter.

A surgical drape includes a flexible and lightweight sheet-like materialto be applied adjacent to an area subject to laser radiation and isformed of a series of densely packed bubbles encapsulated in a matrix ofsilicone to terminate laser radiation. A fabric sheet is attached to thelaser terminating material for comfort an aesthetic appearance.

A surgical sponge includes a flexible and lightweight sheet-likematerial formed of a series of densely packed bubbles encapsulated in amatrix of silicone to terminate laser radiation and is attached to asponge-like surface to be applied adjacent to an area subject to laserradiation. Sheet-like sponges are connected to opposite sides of thesheet-like laser terminating material so as to sandwich the laserterminating material between the two sheet-like sponges.

An endotracheal tube for insertion into the esophagus of a mammalincludes an elongated tube having first and second oppositely spacedopenings to permit the passage of anesthetic gases which may becombustible or support combustion therethrough and is formed of aflexible and lightweight material having a series of densely packedbubbles encapsulated in a matrix of silicone to terminate laserradiation that may strike such elongated tube.

Other aspects of the invention will be made apparent in the drawings andphotographs annexed hereto and the following description thereof as wellas in the claims annexed hereto.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagramatic cross-sectioned illustration showing a series ofdensely packed bubbles encapsulated in a matrix of silicone;

FIG. 2 is a black and white photo-micrograph showing the microstructureof a laser shield consisting of water encapsulated in a matrix ofsilicone;

FIG. 3 is a black and white photo-micrograph showing a greatermagnification of a portion of the laser shield shown in FIG. 2;

FIG. 4 is a black and white photo-micrograph duplicate of FIG. 2 andshows the microstructure of the laser shield after terminating laserenergy;

FIG. 5 is a balck and white photo-micrograph showing the microstructureof a laser shield consisting of glass bubbles encapsulated in a matrixof silicone;

FIG. 6 is a black and white photo-micrograph showing a greatermagnification of a portion of the laser shield shown in FIG. 5;

FIG. 7 is a black and white photo-micrograph showing the microstructureof the laser shield of FIG. 5 after terminating laser energy;

FIG. 8 is a black and white photo-micrograph showing the microstructureof a laser shield consisting of water and glass bubbles encapsulated ina matrix of silicone;

FIG. 9 is a black and white photo-micrograph showing a greatermagnification of a portion of the laser shield shown in FIG. 8;

FIG. 10 is a black and white photo-micrograph showing the microstructure of the laser shield of FIG. 8 after terminating laser energy;

FIG. 11 is a top view diagramatic illustration of a surgical drape whichincludes a laser terminating material;

FIG. 12 is a side elevational view of the surgical drape of FIG. 11;

FIG. 13 is a top diagramatic illustration of a surgical spongecontaining a laser terminating material;

FIG. 14 is a side elevational view of the surgical sponge of FIG. 13;

FIG. 15 is another top diagramatic illustration of the surgical spongeof FIG. 13 and illustrating the application of forceps thereto;

FIG. 16 is a diagramatic illustration of an endotracheal tube formed ofa laser terminating material; and

FIG. 17 is a diagramatic illustration showing use of the endotrachealtube of FIG. 16 as placed in the trachea of a mammal.

BEST MODE FOR CARRYING OUT THE INVENTION

A laser shield 20 includes a matrix of silicone 21 which encapsulates aseries of densely packed bubbles 22 for terminating laser radiation.

The silicone 21 may be selected from any one of a number of commerciallyavailable silicones, such as curable organopolysiloxanes commerciallysold as RTV silicone rubber sealers designed to be used as adhesivesealants under the designations RTV/112 and RTV/118 by the GeneralElectric Co. of Waterford, N.Y., which claims such silicone to be withinthe scope of U.S. Pat. Nos. 3,296,161 and 3,382,205.

In one form, the silicone is conformed to enclose water and isthereafter cured to encapsulate the water within the silicone to providea flexible material which effectively terminates CO₂ laser radiation.

One embodiment encapsulates water in a layer between two layers ofsilicone to provide a sandwiched effect of the water between andsurrounded by silicone. Another embodiment requires mixing or stirringthe water into the silicone to produce water bubbles or dropletsthroughout the silicone to provide a series of densely packed waterbubbles which are encapsulated in a matrix of silicone. This laterembodiment is photographically shown in FIG. 2 wherein a cut-awayportion of the laser shield shows openings where water bubbles ordroplets had been entrapped by the surrounding silicone. The picture ofFIG. 3 shows a close-up of a portion of the laser shield. The picture ofFIG. 4 shows where laser energy evaporated and molded a portion of thelaser shield which effectively terminated such laser energy within theconfines of the laser shield.

It is also contemplated that a solvent, such as mineral spirits may beadded with the water and encapulated by the silicone to function as aninert element when cured without effecting the laser terminatingproperties of the shield.

By way of example and for illustrative purposes only, a laser shield maybe formulated with one part of water and one part of mineral spiritsencapsulated by one part of silicone.

In an alternative embodiment, the bubbles 22 are provided by a series ofdensely packed spherical glass bubbles which are encapsulated in thematrix silicone to provide a flexible and lightweight foam-like materialwhich terminates CO₂ laser radiation without producing a substantialcarbon plume. Such glass bubbles may be selected from any one of anumber of commercially available glass bubbles such as marketed by 3M ofSt. Paul, Minn. as its "general purpose series". The glass bubbles areselected from a range of 20 microns to 200 microns and are denselypacked when encapsulated within the silicone. The bubbles should bedensely packed within a range of from 1.95×10³ bubbles per each cubiccentimeter to 1.25×10⁸ bubbles per each cubic centimeter. The glassbubbles are generally selected from a size range of from 20 microns to200 microns.

The picture of FIG. 5 illustrates densely packed glass bubbles which areencapsulated in a matrix of silicone. The picture of FIG. 6 is of highermagnification and it is noted that the broken glass bubbles were causedwhen cutting the laser shield in order to take the magnified picture.The micro-photograph of FIG. 7 shows another view of the laser shield ofFIG. 5 which has terminated two bursts of laser energy. Laser energy at80 watts has been found to be terminated within 0.6 to 0.9 millimetersof penetration into the laser shield.

By way of example and for illustrative purposes only, a laser shield maybe formulated with 30 milliliters of silicone which encapsulates 18milliliters of glass bubbles. Alternatively, 30 milliliters of siliconemay be used in combination with 18 milliliters of glass bubbles and 30milliliters of a solvent such as mineral spirits to encapsulate theglass bubbles within the silicone.

Another embodiment provides a laser shield wherein water bubbles andglass bubbles are both encapsulated in silicone. The photo micrographsof FIGS. 8-10 illustrate water and glass bubbles which are encapsulatedin silicone. In some cases, the glass bubbles are enclosed in a waterbubble which, in turn, is encapsulated by silicone. The micro-photographof FIG. 10 illustrates how the laser shield which employs encapsulatedwater and glass bubbles has terminated two separate incidences of laserenergy.

The use of bubbles and/or encapsulated water has been found to eliminatethe issuance of black films possibly containing carbon or carcinogenicswhich are sometimes produced by silicone alone when subjected to laserenergy. Thus, the laser shield which encapsulates densely packed bubblesand/or layers of water within silicone is an extremely desirable lasershield for use in medical applications. For example, a surgical drape 25includes a flexible and lightweight sheet-like material 26 which is tobe applied adjacent to an area subject to laser radiation and is formedof a series of densely packed bubbles encapsulated in a matrix ofsilicone. A fabric sheet 27, such as conventionally used in surgery, isattached by adhesive or other suitable fastening means to the laserterminating material 26 to form the surgical drape 25. Such surgicaldrape 25 may be safely used in areas where laser energy is being appliedto a patient so as to shield the patient from unintended laserradiation, such as might occur by the accidiental movement of the lasersource.

A surgical sponge 30 includes a flexible and lightweight sheet-likematerial 31 formed of a series of densely packed bubbles encapsulated ina matrix of silicone to terminate laser radiation. A pair of sheet-likesponges 32 and 33 are attached to opposite sides of the laserterminating material 31 to form a small pad which can be cut into anydesired configuration and placed within or near an organ which is beingtreated or operated upon by laser energy.

An endotracheal tube 35 has first and second oppositely spaced openings36 and 37 to permit the passage of anethetic gases therethrough and isformed of a flexible and lightweight material having a series of denselypacked bubbles encapsulated in a matrix of silicone to terminate laserradiation that may strike the elongated tube. The endotracheal tube 35may be inserted into an esophagus 38 so that end 37 is located adjacentto the lungs 39 while a balloon 40 receives pressurizing gas through aballoon inflation tube 41 to provide an airtight seal between theendotracheal tube 35 and the esophagus 38. Thereafter, a lasertransmitting apparatus is inserted into the body cavity adjacent to theendotracheal tube 35 and laser energy is transmitted with the resultthat any unintended laser energy which impinges the side walls of theendotracheal tube 35 will be terminated, preventing combustion of theanesthetic gases within the endotracheal tube.

It is contemplated that when glass bubbles are utilized, a flameretardant gas, such as an inert gas, may be placed therein to furthersuppress laser energy.

Various modes of carrying out the invention are contemplated as beingwithin the scope of the following claims which particularly point outand distinctly claim the subject matter which is regarded as theinvention.

We claim:
 1. A laser shield, consisting essentially ofa dispersion ofwater in liquid droplet form encapsulated in a matrix of silicone rubberto provide a flexible material to terminate laser radiation withoutproducing a substantial carbon plume.
 2. A laser shield, comprisingamatrix of silicone rubber, and a dispersion of densely packed bubblesencapsulated in said silicone rubber for providing protection from laserradiation, said bubbles are densely packed within a range of 1.95×10³bubbles per cubic centimeter to 1.25×10⁸ bubbles per cubic centimeter,with at least a portion of said bubbles including water in liquiddroplet form.
 3. A surgical drape, comprisinga flexible and light weightsheet material to be applied adjacent to an area subject to laserradiation and formed of a dispersion of densely packed bubblesencapsulated in a matrix of silicone rubber to terminate laserradiation, said bubbles include glass bubbles and water in liquiddroplet form.
 4. A surgical drape, comprising a flexible and lightweight sheet material to be applied adjacent to an area subject to laserradiation and formed of a dispersion of densely packed bubblesencapsulated in a matrix of silicone rubber to terminate laserradiation, said bubbles include water in liquid droplet form.